The present invention relates to a surface light source device and other display device employing the surface light source device. More particularly, the present invention relates to the display devices such as a signboard and an induction light employing a transmittance type of a liquid crystal display and a display a panel, which displays a letter or a figure, and the surface light source device supplying illumination light, which employs a plurality of dot light sources such as a light emitting diode, to the display device.